Metallizable monoazo-dyestuffs and complex metal compounds



assess? Patented May 27, 1958 fiice 1 2,836,587 METALLIZABLE MONOAZO-DYES'IUFFS AND COMPLEX P/LETAL COMPOUNDS Arthur Buehler, Rheinfelden, and Christian Zickendraht, Binningen, Switzerland, assignors to Cilia Limited, Basel, Switzerland, 11 Swiss firm No Drawing. Application October 17, 1955 Serial No. 541,043 Claims priority, application Switzerland December 7, 1951 19 Claims. (Cl. 260-147) This is a continuation-in-part of our copending application Ser. No. 323,502, filed December 1, 1952, and now abandoned.

According to this invention valuable new metallizable monoazo-dyestufis are made by coupling a diazo compound of an amine free from sulfonic acid and carboxylic acid groups and corresponding to the general formula in which R represents an aralkyl or aryl radical, and R represents a benzene radical in which the hydroxyl and amino groups are in ortho-position relatively to one another, with a coupling component free from sulfonic acid and carboxylic acid groups and capable of coupling in a position vicinal to a hydroxyl group. a

The new amines of the general Formula 1 used as starting materials may contain in the radical R and/or advantageously in the radical R further substituents, such as halogen atoms, for example chlorine; allay] groups, for example methyl; alkoxy groups, for example methoxy; nitro groups; CO-alkyl groups or acylamino groups, for example, acetylamino. Those radicals must not contain sulfonic acid or carboxylic acid groups. These new starting materials can be prepared, for example, from salts of ortho-nitro-halogen-benzene sulfinic acids, especially from alkali salts of ortho-nitro-chlorobenzene sulfinic acids, or from ortho-nitro-halogen-benzene sulfonic acid halides. For example, the sodium salt of a Z-nitro-l-chlorobenzene sulfinic acid may be reacted with an aralkylhalide, especially an aralkyl chloride, to form the corresponding sulfone, replacing the chlorine atom in the l-position of the resulting sulfone by a hydroxyl group by reaction with an alkali hydroxide or alkaline earth metal hydroxide, and finally converting the nitro group in the 2-position into an amino group by a method in itself known. 2-amino-l-hydroxybenzene-S-sulfones can be obtained from the corresponding ortho-amino-hydroxybenzene sulfinic acids by converting the corresponding oxazolone derivative, for example, intov its sodium salt, reacting the latter with an aralkyl halide, and hydrolyzing the oxazolone ring in the resulting sulfone by means of an alkali to liberate the amino and hydroxyl groups. The compounds of the Formula 1, in which R represents an aryl radical, can be prepared from ortho-nitro-halogen-benzene sulfonic acid halides. Advantageously an ortho-nitro-chlorobenzene sulfonic acid chloride is condensed in the presence of a Friedel-Crafts catalyst such, for example, as FeCl or A101 with or without the use of a suitable solvent such as carbon disulfide or the like, with the selected aromatiecompound, which is advantageously of the benzene series, for example, with benzene, toluene, xylene, an alkoxy benzene or the like, the chlorine atom bound in ortho-position to the nitro group in the resulting sulfoneis replaced bya hydroxyl group by reaction with an'alkali hydroxide or an alkaline earth metal hydroxide,' and finally the nitro-group in ortho-position relatively *tothe'hydroxyl group introduced is reduced to an amino group by a method in itself known. In

this case also it is possible instead of starting from an ortho-nitro-halogen-benzene sulfonic acid halide, to start from the corresponding ortho-amiuo-hydroxy-compound which contains the amino and hydroxyl groups in the form of an oxazolone ring, so that after condensation to form the sulfone by the Friedel-Crafts methodit is only necessary to hydrolyze the oxazolone ring in order to obtain the desired ortho-amino-hydroxybenzene aryl sulfone.

As examples of compounds of the Formula 1, obtainable by the methods described above and serving as starting materials for the present process, there may be mentioned:

Z-amino-1-hydroxy-4-nitrobenzene-dphenyl sulfone, 2- amino-l-hydroxy-4-chlorobenzene-S- or -6-phenyl sulfone and 2-amino-l-hydroxy-4-nitrobenzene-tS-benzyl sulfone.

Especially valuable results are obtained with B-amino- 4-hydroxydiphenyl sulfone, 4-amino-3-hydroxydiphenyl sulfone, 2amino-l-hydroxybenzene-4- or -5-benzyl sulfone, 3-amino-4-hydroxy-4-methyl 1:1 diphenyl sulfone, 3-amino-4-hydroxy-4'-methoxy-1:l-diphenyl sulfone, 4-amino-3-hydroxy-4'-methyl-l:l-diphenyl sulfone and 3amino-4-hydroxy-4-chloro-l:l'-diphenyl sulfone.

As coupling components for the present process there come into consideration compounds free from sulfonic acid and carboxylic acid groups and capable of coupling in a position vicinal to a hydroxyl group, that is to say, compounds containing a phenolic hydroxyl group and compounds whichowe their capacity for coupling to a keto-methylene group. These latter compounds may contain the keto-methylene group in an open chain or in a heterocyclic ring. There may be mentioned for example:

(a) Para-substituted hydroxybenzenes such as 4-methyl-, 4-chloro-, 4-methoxy-, 3:4-dimethyl-, 4-tertiary-amylor 4-acetylamino-l-hydroxybenzene, 4-methyl 2 acetylamino-l-hydroxybenzene. Dihydroxybenzenes such as resorcinol, hydroxynaphthalenes such as 2-hydroxynaphthalene, 2:6-dihydroxynaphthalene, Z-hydroxy-fi-bromoor -6-methoxynaphthalene, 2-hydroxynaphthalene-4-, -5-, -6- or -7-sulfonic acid amide, 1-hydroxy-4-methylnaphthalene, 1-hydroxy-5-chloronaphthalene, 1-hydr0xy-5:8-dichloronaphthalene, l-hydroxynaphthalene-3-, -4- or -5-sultonic acid amide; 1-hydroxy-4-methylnaphthalene-8-sultonic acid amide, and also l-acylamino-7-hydroxynaphthalenes such as l-acetylamino l-n-butyrylamino-, l-benzoylamino-7-hydroxynaphthalene or 7-hydroxynaphthyl-(1)-carbamic acid methyl or ethyl ester.

(b) Pyrazolones such as 3-methylor 3phenyl-5- pyrazolone, 1-n butyl3-methyl-5-pyrazolone, 1-phenyl-3- methyl-S-pyrazolone, 1-phenyl-3-methy1-5-pyrazolone-3'- or -4'-sulfonic acid amide, 5-pyrazolone-3-carboxylicacid amide, 5-pyrazolone-3-ca'rboxylic acid methyl-, ethyl-, isopropyl-, secondary-butyl-, tertiary-butylor n-butylamide, 5-pyrazolone-3-carboxylic acid pheuylamide or tolylamide, 1-phenyl-5-pyrazolone-3-carboxylic acid amide or methylamide, barbituric acids such as barbituric acid itself dihydroxyquinolines such as 2:4-dihydroxyquinoline, acylacetic acid esters or amides such as acetoacetic acid amide, acetoacetic acid methyl-, n-butyior phenylamide, acetoacetic acid dimethylamide, acetoacetic acid ortho-chlorophenylamide, 1-acetoacetylaminobenzene-2-, -3- or -4-sulfonic acid amide, benzoylacetic acid amide. Among these compounds valuable results are obtained, more especially, by coupling those which contain a sulfonic acid amide group with the sulfones of high molecular weight mentioned.

The amines of the Formula 1 can be diazotized in the usual manner, for example, with the use of sodium nitrite and hydrochloric acid. The resulting diazo compounds can be coupled with the aforesaid coupling components in the usual manner, for example, in an alkaline medium.

After the coupling reaction the dyestuffs can easily be separated fromthe coupling mixture by filtratiomsince theyusually are only slightly soluble in water.

Themonoazo-dyestults obtainable as described above' are new. They containno sulfonic acid or'carboxylic acid groups and correspondtothe general formula (2) i o on i in which-R represents an aralkyl or aryl radical, R 'represents a benzene radical containing the aminoand 1 hydroxyl groups in ortho-position'relatively to one another, and R represents the radical of a coupling component which isbound to the azo linkage in a position vicinal' to a .hydroxyl group. 7 l

They are sufficiently soluble in the form of their alkali compounds for dyeing from dyebaths which require no addition of acid. Accordingly, they are principallysuitable for dyeing by the single bath chroming process,

' but in some cases they also yield goodiresults in dyeing by the after-chroming process. I

dyestuifs in substance-with an agent yielding metal, for example, an agent yielding iron, nickel, aluminum, copper and especially cobalt or chromium. The metallization, for example, chroming, may be carried out in thecase of the more easily soluble dyestufis,.for example, those tcont aining a sulfonamide group, by treatment with a salt of trivalent chrcmium such as chromium acetate, chromium fluoride or a chromium. sulfate, in such manner that a chromium compound is. produced which contains aboutfone atom of chromium bound in with one molecule of dyestuff. J

For this" purpose the chromingmay. be :carried out' in anacid medium, under atmospheric pressure ,for, a long period, for example, several hours, and at the boiling temperature .of. the reaction mixture, or at a higher temperature and in the presence of a solvent such as alcohol; and under pressure. g l

'Especially, valuable complex. metal compounds-are unioniwith substantially;2 molecules 1 of monoazo-dye stufi g For this purpose itis generally desirable touse The invention also includes treatment ofwthe monoazocomplex union obtained bycarrying out themetallization with an agent yielding cobalt'or chromium under conditions such that the resulting cobaltiferous or chromiferousazo dyestufir contains one atom of. cobaltor' chromium'in complex for every ,2, molecular proportions. of a v dyestuifl. of the. l

Formula Zor of a mixture of about il molecularproportion mach of twogdilterent. dyestuffs of which at least one corresponds to the; general Formula 2, aquantity of. an agent yielding metal 'containingone atomic propormetal Compoundsyvhichare stabletdwards alkaline media 2,836,587 a p I temperature of the reaction mixture, if desired in the presence of suitable additions, for example, .saltsaof. organic acids, bases, organic solvents or other agents assisting the formation of complexes. The metallization described above may, for example, be

carried out upon a single dyestutf of the Formula 2.

However, it is also possible and in many cases is of adpreferably two molecules of monazo-dyestuff in complexunion with one atom of cobalt or chromium, and in which at least one of the monazo-dyestulf molecules corresponds to the general Formula 2; Especially valuable are the cobalt and chromium compounds of this kind which contain two molecules of the same nionoazo-dYestuff of the Formula 2.

7 These new cobalt and chromium compounds are s'oluble in water and weakly'acid media, 'and are'indeed more soluble than the dyestuffs from which they are prepared.

-They. are suitable for dyeing various materials, such as plastic masses, resins, waxes, lacquers and. th'e'like, but

especiallyifordyeing or printing animal materials such as silk, leather and especially wool, and also for dyeing or printing synthetic materials composed of superpolyamides or-superpolyurethanes.

They are-suitable above all for dyeing from weakly alkaline,neutral or weakly acid, for example, acetic acid, baths. The dyeings produced are' distinguished by the special purity of 1 their tints, good level character, good properties of wet fastness and very good fastne'ss to light. e

V The following examplesillus'trate the invention, the parts and percentages beiiig by weight unless otherwise, stated and the relationship of partsby'weight to parts by volume being the same as that of the. kilogram-tomeliter Example 1 256 parts of, l-chloro 2enitrobenzene4rsulfonie 1 acid;

chloride are dissolved in 500'parts of dry be'nzene and mixed gradually at 40 C. with l40.parts of alum inum, chloride, whereupon hydrogen chloride is evolyed. The mixture is maintained at 40-50" C. ,for, 3-4 hours. IThe dark liquid is poured onto ice, and the benzeneis expelled with steam. Aftercooling, theresidueiis filtered'andLthe filter residue is washed with water The resulting 1- chloroQ-nitrobenzene-4 phenyl-sulfone, which melts at tion of the metal and/or'tocarry out the metallization in w'eakly acid to alkaline mediumkIConsequently "are especiallysuitable for carrying'out' the process, for.

example, cobalt or advantageouslychromium compounds I complex union. As examples of aliphatic dicarboxylic acids' and 'hydroxycarboxylic acids therev may :be menof aliphaticudicarboxylic acids or hydroxycarboxylic acids 1011 abovejall chromiumi compounds of aromatic orthohy droxy carboxylic acids which contain ,the' metal v in.

tinned inter alia oxalic acid, lactic, acid, glycollic acid,

citric acid and especiallyi tartaric acid :and, among .the aromatic hydroxycarboxylic acids there may be mentioned those ofthe benzene serim such as 4-, 5'- or} V 6-methyl;l-hydroxybenzene-2-carboxylic acid and'above all T firdrqs beaz nea box aci tsel As ag t i diaswbaltfm:P ep n qmp xcg npeua s o t kind. last mentioned there also comei O 1 mp as lts-o d ra em c b u ascoba t sulfat icqbalt e a e .o im al or ate- Conversion of taeidyestufis,

o t el m l x metal c mpounds: is advantageonsl'yi carried outwith the aid; of heatgunderj atmospheric or super-atmospheric pressure, for example, :atthe' boiling v ansid aiatien 125-126" C. after recrystallization fromalcohol; is heated while still moistinflSOO parts'oflcaustic' 'sodasolution of;

10 percent strength 'for 3 hours at. the boil untiliza prac=' ticallyclear solutionfis'obtained; The solution isacidi tied with hydrochloric acid, and the precipitated 4-hy-1 droxy-3-nitro-l:l diphenyl sulfone is filtered oif washedvvith Water. After recrystallizationfromalcohol it is in the form of yellow crystals which-melt at 132434?: CI, .Finally the product is reduced in usualmanner with sodium sulfide, or'subjectedto catalytic reduction with hydrogen in the presence of nickel. '4-hydroxy+3 amino-.1:l-diphe'nyl sulfone is obtained in the form -of f a pale. powder, which after recrystallizationfrom alcohol melts at l59l6l C. a a t Q j T 24.9 parts oftheigre'sulting 3-amino 4 hydroxy l: 1'-di phenyl s'ulfone are diazoti zed in the usual mariner in solution' in hydrochloric acid with sodium nitrite, The diazo compound is neutralized with sodium carbonatej and coupled with a'solution prepared from 19,part s:o f:;5-f. l '1 pyraz olbn-B-carbdxylic acidenebutylamide, j parts} of,

water, 4'parts of sodium hydroxide and 5 parts of sodium; v carbonate. When the coupling has finished,,the' precipiez; I l

tated'dyestutt is filtered ofhwashed with dilute sodium:

chloride solution and dried. There is obtained a dark powder which dissolves in hot water with a red-brown coloration and in concentrated sulfuric acid with a redorange coloration. The dyestufi which corresponds to the 2 N-solution of sodium hydroxide and 15 parts of a solution of sodium chromosalicylate containing 2.6 percent of chromium, and the mixture is boiled under reflux for about 4 hours. By neutralizing the chroming mixture f rmula with dilute acetic acid the chromium compound is com- H0 pletely precipitated. The dyestufi chromium complex, 03 after being filtered ofi and dried, is a dark red powder which dissolves in hot dilute sodium carbonate solution with a red coloration and in concentrated sulfuric acid c= with a yellow-orange coloration. The chromium com- & O NH (OHB)SCHB plex dyes wool or fibers of superpolyamides from a weakly alkaline, neutral or weakly acetic acid bathpure red tints so which are fast to light and washing. dyes wool by the after-chroming process or single bath r Examplej 7 611mm Process P fed tints which are Very fast to In order to convert the dyestutf obtained as described washing and light. in the second paragraph of Example 1 into its complex The -Py y acld-ll-blltylamlde used cobalt compound, 4.43 parts of the dyestuif are heated in his example y be P p as f0119W$1 at 80 C. with 150 parts of water and 5 parts by volume P Of -py 9 y acld yl ester of a 2 N-solution of sodium hydroxide, and mixed with are heated m parts of n-butyl m for a 10118 111918 i 11 parts of a cobalt sulfate solution having a cobalt con- -95 C. under reflux- The exc ss f ty 1s tent of 2.95 percent. After heating for about /2 hour then distill d the residue is dlssolved e If at -90 c. the formation of the complex is finished. sired, llfilltllfe filtered f f lmpllrltles fi By neutralization with dilute acetic acid the resulting cofiltrate 1s acldlfied W Y P 301d: The 16511111118 25 balt complex of the dyestufi is completely precipitated. -PY Y acld-n-bqtylarmde melts l?- The filtered and dried dyestuif is a dark brown powder y f Wlth decomposlfion, after fecl'ystalllwhich dissolves in hot dilute sodium carbonate solution Zatlon from ethyl alcohol with an orange-brown coloration, and dyes wool from The Same P Oblalned y SuSPeIldmg -PY a neutral to weakly acetic acid bath orange-brown tints olone-3-carboxylic acid in an inert solvent such as chloro- 30 which are very fa t to light en adding QhOSPhOIUS '(Tlchlonde the l'esllltlng In the following table are given the properties of furu p d simultaneously or subsequently treatmg thet dyestufis and metal complexes obtained in an analwith n-butylamine. ogous manner. In column a are given the tints of the Example 2 dyeings obtainable on wool by the single bath chroming 4.43 parts of the dyestufl obtained as described in the 35 process, under b the tints obtained with the chromium second paragraph of Example 1 are suspended in 150 complex and under 0 the tints of the cobalt complex on parts of water, then mixed with 5 parts by volume of a wool or fibers of superpolyamides:

N0. Blaze-components Azo-components a b 4.-

1 NH: --N\ orange orange yellow brown.

NCH2CH2CH1CH! I Grit-0o SO2Co l OH 2 @NH: OH violet brow-11...- violet brown...- bordeeux.

orCuHs OH NHCOCH: 3 @NH: grey grey violet grey.

SOa-CtHt 4 NH: orange orange yellow brown.

H:OC t-GOES F 5 NE: C-N\ d0 -.do Do.

I N SOtNHfl CHr-OC SOs-00H;

" V CH1 red violet brownred yellowish 7 deaux. 7

yellow.

brownish bor- Y Vdeaux.

orange brown.

No. Diem-components Arc-components a b c O-NH 15..." NH: H2C\ .--..d0 "do D0,

(|3=N C ONH(CH2)a-0H;

/O O-NH 16...--- V NHz H2C\ dO .110 D0.

('3 N C ONH(OH2)a-CH /O O-NH 17--- N112 HzC\ d0 --d0 D0.

(1): CONHOHCH2OH s'o The dyestufi obtained from the diazoand azo-components listed in the above table under N0. 5 corresponds to the formula l l S O zNH: =N

. CH3 Q the dyestuff from the component listed under N0. 6 corresponds to the formula and that obtained from the components listed under N0. 8 corresponds to the formula ooorn with a brown-red coloration.

The complex chromium compound obtained from the I The still moist l-chloro-2-nitro-benzene-4-(4'-methyl)- phenylsulfone so obtained is then heated at the boil in 500 parts of a caustic soda solution of 10% strength for 3 hours until the solution is practically clear. The latter is reduced with sodium sulfide according to the usual method. 4 hydroxy 3 amino 4' methyl 1:1- diphenyl-sulfone is obtained as a grey powder which melts at 168-170 C. after having been recrystallized from alcohol. V

The 4-hydroxy-3-amino-4'-chloro1 l'-diphenylsulfone can be prepared as follows:

256 parts of 1-chloro-2-nitrobenzene-4-sulfonic acid chloride are dissolved in 500 parts of dry chlorobenzene and gradually mixed with 140 parts of aluminum chloride at 40-45 C. The mixture is heated for 24 hours at 55-60 C., hydrogen chloride evolving. The dark reaction mixture is poured on to ice and the chlorobenzene expelled with steam. The resulting, still damp 1-chloro-2-nitrobenzene-4-(4-chloro)-phenyl sulfone is heated at the boil in 500 parts of a caustic soda solution 1 of 10% strength for 4 to 6 hours until the solution is practically clear. fide according to the usual method. The 4-hydroxy-3- amino-4-chloro-1:1'-diphenyl sulfone is obtained in the form of a grey powder which has a melting point of 178 C. when recrystallized from alcohol.

Example 4 24.9 parts of 4-amino-3-hydroxy-1:1-diphenylsulfone are diazotized in the usual manner in a hydrochloric acid solution with sodium nitrite. The diazo compound is neutralized with sodium carbonate and coupled with a solution prepared from 19 parts of 5-pyrazolone-3-carboxylic acid-n-butylamide, parts of water, 4 parts of sodium hydroxide and 5 parts of sodium carbonate. When the coupling is finished, the completely precipitated dyestuff isiiltered off, washed with dilute sodium chloride solution and dried. There is obtained a brown powderv which dissolves in water and in concentrated sulfuric acid The latter is reduced with sodium sul- I hayinggpod properties of fasltness,

above dyestutf by the method described in Example 2 is a dark red powder, which dissolves in water with a red coloration and in concentrated sulfuric acid with an orange coloration, and dyes wool from a neutral or weakly acetic acid bath strong bordeaux tints of good fastness. 7

The 4-amino-3-hydroxy lrladiphenyl-sulfone 'used in this example may be prepared as follows:

229'parts of benzoxazolone sulfochloride (obtained as described in French specification No. 873,201 by treating benzoxazolone with chlorosulfonic acid while heating) reflux with 500 parts. of sodium hydroxide solution 'of percent strength for 3 hours until a clear slightly brownish solution is obtained. The solution is acidified with acetic acid, whereupon a strong evolution of carbon dioxide sets in. The precipitated finely crystalline 4- amino-3-hydroxy-l :1 -diphenylsulfone;i s filteredofr, I and washed with dilute sodium chloride solution and dried. When recrystallized from alcohol it melts at 189-190 C.

' ErampleS 4.43 parts of the dyestufi obtained as described in the V first paragraph of Example 1 and 4.21 parts of the dyeof water, then mixed with 10 partsiby volumeof 1a 27N- solution of sodiumhydroxide and parts by volume of a solution of sodium chromosalicylate containing 2.6 1 percent chromium, and the mixture is boiledunderreflux 1 "for about? hours. By neutralizing the chroming mixture with dilute acetic acid the chromium compound is] completelyprecipitated; When dry; it isa :red pow den which dissolves in water with an orange coloration and in concentratedsulfuric acid with a yellowicoloration,

and dyes wool from aneutral to weakly acetic acid b'ath fullorange-red..tints of good fastnessp e n Example 6 V parts l of 2 am'ino.-1-hyd.roxybenzene;1-benzylsul-a.

fone are 'dissolvedin 100 partsof water and 13.3 parts of sodiumihydroxi'de solution of 5 30percent strength, and k 7 after, the additionof 6.9 parts. of sodium nitrite the ture is.,slowly' introduced dropwiseinto 30 parts of .hy-

dr'ochloric'lacid of 30 percent strength and 150 parts of ice. 'In this'nianner'thereis obtainedthe sparingly so1 u' ble. dia'zo. compound. of. 2-amino-1-hydroxybenzene 4- 'benzyl sulfone. It. is filtered ofi and introduced in the} form of a'rnoistifilter. cal're in to v atsolution prepared from r 18 parts of,1ephenyl 3methyl-5epyrazolone, 100 parts of' water, 6.7 parts of sodium hydroxide solution "of 30 1 percent strength and 20 parts of a sodium carbonate 5 solution of 10 percent strength; 'The coupling proceeds formed very rapidly; When .it is firnshed' the dyestuff is separated by filtering with suction.

After dissolving the resulting'dyestufi in 0 pa rtsi wa ter and? 26.5 {parts ofi'sodiumhydroxide solution; of 30'; l percentstrength itis metallized by heatingit'for 3 hours;

with :120 p arts of a: solutionjof sodium chromosalicylate it hayingachromium content of--2.6 percent. Thec'omplex V V is is'olatedxby. the addition-of sodium chloride -When -dry 'itisabrownposvder whichdissolves in concentrated sulflllli flfild with a yellow coloration and in-sodium .car-

dyes wool from a neutral'oriaceticfiacid bath orange tints,

is bar i sirt i i 'h diss l ieii w rera d I "parts of sodium nitrite.

- By treating the dyestufi obtained as described 11111116.

first paragraph above with an agentyielding cobalt such as cobalt sulfate, the cobalt complex is obtained in the form of a yellow-brown'powder"which dyes "wool ffoin a' neutral or acetic acid bath yellow-brown tints'having good properties of fast ness Z-amino-l-hydroxybenzenet-benzyl sulfone is obtained' by condensing'2-nitro-1-chlorobenzene-4-sulfinic acidfwith benzyl chloride, hydrolyzing the resulting condensation Example 7 29.75 parts of 4-chloro-2-amino:lehydroxybenzene-6- benzyl sulfone are dissolved in 200 parts of water while 7 adding 4.4 parts of sodium hydroxide, and mixed with 6.9 The resulting solution is added dropwise to 120 parts of. hydrochloric acid of 10% strength, theternperature of the diazo solution mixture being maintainedbetween 0-5" C. by the addition of ice.

' The diazo compound neutralized with sodium carbonate is combined with a solution prepared from 17.4 parts of l phenyl-3-methyl-5 pyrazolone, parts. of water, 4

parts of sodium hydroxide and 5 parts of sodium carbonate. After coupling is complete, the sparingly soluble dyestuff is filtered, washed with a dilute solution of sodium chloride'and dried. A brown powder is obtained which dissolvesin waterwith a red coloration andinconu centrated sulfuric acid with a yellow brown-coloration.

.The complex chromium compound obtained fromthis dyestuft according to the method describedin Example 2 is a red powder which dissolves in water with a red" coloration and in concentratedsulfuric acid with an orange coloration and dyes "wool from a neutral or weak ly acetic acid bath in brown-red tints havinggood fastness properties. r V V V If the dyestuff described above is converted into the co mplex'cobalt compound accordingto the method described in Example 3, abrown powder isobtained which dissolves in water and in concentrated sulfuric acid with a yellow-brown coloration and dyes wool from a neutral phosphorus pentachloride into the sulfochloride of melting point 192-193 1C;, and the corresponding sulfinic acid of ,inelting point 289-290? C. is prepared.- Finally the sulfinic acid is mixed with 'benzyl 'chloride andthe.result-- ing condensation product of melting point 236 C. is hydrolyzed with dilutesodium hydroxide solution.

When in the firstparagraph of ;this exarnple there are used 28.35 parts of ;55chloro-3-amino-2 hydroxy-1 :1'-di'- phenyl sulfone instead of-the 4-chloro-2-amino-1-hydroxy-, benzene-fi-benzylsulfone, apmetal-free dyestutf is obtained as a red powder which dissolves in water with a red coloration'and in'concentrated sulfuric acid with an orangecoloration 1 which dissolves in waterwjith a r'edcolora'tioh' andjin coni and; dyes 'wool from aneutralor weakly'aeeticlacid bath Q l t ntshavin'ga good f astnes's propertiegfwhilst meg-ear responding. cobaltcomplex obtained according E1:

in concentrated sulfuric acid with a yellow-brown coloration and dyes wool from a neutral or Weakly acetic acid bath brownish orange tints having good fastness properties.

The -chloro-3-amino-2-hydroxy-l l'-diphenyl sulfcne can be obtained from the 4-ch1oro-2-amin0-1-hydr0xybenzene-6-sulfochloride of melting point 192193 C. by reacting it with benzene according to Friedel-Crafts and subsequent hydrolysis.

Example 8 2 parts of the chromiferous dyestufl obtainable as described in Example 2 are dissolved in 4000 parts of water, parts of crystalline sodium sulfate are added, and 100 parts of Well wetted wool are entered at 40-50 C. in the dyebath so prepared. 2 parts of acetic acid of 40 percent strength are then added, the temperature is raised to the boil in the course of /2 hour, and dyeing is carried on for 4 hour at the boil. Finally the wool is rinsed with cold water and dried. The wool is dyed a level pure red tint of good fastness to washing and light.

The same dyeing is obtained by dyeing from a neutral bath, that is to say, without the addition of acetic bath to the bath.

A pure red dyeing is also obtained by using instead of wool, superpolyamide fibers (nylon).

What is claimed is:

1. A dyestuff selected from the class consisting of a monoazo dyestuff free from sulfonic and carboxylic acid groups and corresponding to the-formula wherein R represents a benzene radical, n represents a whole number which is at most 2, R represents a benzene radical bound to the azo linkage in ortho-position relatively to the hydroxyl group and A represents the radical of a coupling component bound to the azo linkage in a position vicinal to a hydroxyl group, a chromium and a cobalt complex of said monoazo-dyestuff.

2. A complex chromium compound of a monoazo-dyestuif free from sulfonic acid and, carboxylic acid groups and corresponding to the formula wherein R represents a benzene radical, n represents a whole number which is at most 2, R represents a benzene radical bound to the azo linkage in ortho-position relatively to the hydroxyl group and A represents the radical of a coupling component bound to the azo linkage in a position vicinal to a hydroxyl group.

3. A complex cobalt compound of a monoazo-dyestufi free from sulfonic acid and carboxylic acid groups and corresponding to the formula wherein R represents a benzene radical, n represents a whole number which is at most 2, R represents a benzene radical bound to the azo linkage in ortho-position relatively to the hydroxyl group and A represents the radical of a coupling component bound to the azo linkage in a position vicinal to a hydroxyl group.

4. A complex chromium compound of a monoazo-,

dyestufi free from sulfonic acid and carboxylic' acid groups and corresponding to the formula wherein R represents a benzene radical and R the radical of a 5-pyrazolone bound to the azo linkage in 4-position.

5. A complex cobalt compound of a monoazo-dyestufi? free from sulfonic acid and carboxylic acid groups and corresponding to the formula wherein R represents a benzene radical and R the radical of a 5-pyrazolone bound to the azo linkage in 4-position.

6. Acomplex cobalt compound of a monoazo-dyestufi free from sulfonic acid and carboxylic acid groups and corresponding to the formula wherein R represents a benzene radical and R the radical of an amide of an aliphatic B-keto-carboxylic acid bound to the azo linkage in a-position.

7. A complex cobalt compound of a monoazo-dyestuflf free from sulfonic acid and carboxylic acid groups and corresponding to the formula wherein R represents a benzene radical and R the radical of a 3-methyl-5-pyrazolone bound to the azo linkage in 4-position.

9. A complex chromium compound of a monoazo-dyestufi free frorn sulfonic' acid'a'nd carboxylicacid groups stuff-free fronr'isulfonic-"acidand ca rboxylic acid groups and'corresponding to the formula andcorresponding to theformula 1 r i 7 e OH V VI *rCHa' N=NRz 7 a m I =N-C r dyestuflfreefrom sulfonic acid and carboxylic acid groups T wherein R represents a benzene radical and R the radical of"3-inethy1-5 pyrazolonebound to the azo linkage in 4 position. f

10 A complex chromium compound ofa monoazowherein R and R3 each represent a benzene radical.- '15. A complex cobalt compound; of the monoazo-dyestufi of the formula- 1 1 I. 1 and corresponding to the formula 7 5 (7 CHr V V stufi of the formula 1" wherein R represent a benzene radical and R the r'adica'l w p r 7 p 7 HO 7 of a 5-pyrazo1one-3-carboxylic acid amide.

'11. A complex chromium compound 'of a monoazodyestuff free from -sulfonicacid and carboxyli'c 'acid' 30 groups and corresponding to the formulai" -16; A complex cobalt compound of the'monoaao-dy 7 17. A complex chromium compound of the 'monoazoe dyestnfi of the formula V 1 l r O-NH 7' 40 wherein Rrepresents a benzenerradicalrand R -theEradicaI i of a 'l-aryl-3-methy1-5pyraz0lone bound to. the azo link i =7 7 V I age in 4-position and containing anarojmatically bound; V f E m I V sulfonicfacidalnide group. r t N 6 12. A complex chromium compound of a monoazo-f dyestufi free from sulfonic acid and carhoxylic'acid groups; i

and corresponding to the formula 18. A complex chromium compound of the monoazo- V dyestufi of the formula OH Ho 7 .r 3' C NH V V OH f. V

' g n a N N C\ l N=NG 1 N H r 7 r V V eGO-N H(GH:);CH| VO==O r V V V 7' ort 7 V V wherein R represents a benzene radical a'ncl'X an alkyl A complex chromium fi p d 0f th m l a q'l. r groupaof low molecularweight. y yest fi 9f i118 Ql'lmlla' V A I 7 13. A complex chromium compound of a'monoazo 7 HO V dyestufi; free from sulfonic acid and carhoxylic acid V V re groupsiandcorresponding to the formula a i i r e 3y J; N: -0 .7 7

HO 7 '7 s n z OH C=N 7 I 7 CNRrSOzNH; 7 I 7 gm l 1 0 r t g V 7 j r I l V References Cited in the file of this patent V V V V. f a UNIIEDISIATES PATENI S V 7 V V R 7 I U 2,353,675 1 'Knecht'e; July 71s; 1944 7 wherein-R and R each represent a benzeneradical; 2,551,056 3 g-Schetty May 1; 1951?: '14,. Apomplex cobalt compound of a monoazo-dye-i f 2,683,707. .eBrassel' Ju1yt1-3 71954:? 

1. A DYESTUFF SELECTED FROM THE CLASS CONSISTING OF A MONOAZO DYESTUFF FREE FROM SULFONIC AND CARBOXYLIC ACID GROUPS AND CORRESPONDING TO THE FORMULA 